The invention concerns a data router able to handle different communication protocols. It is notably applicable to the handling of air traffic management data.
Air traffic density has reached a very high level, while air safety requirements are becoming increasingly stringent. Modern-day air traffic management therefore involves the processing of large quantities of data, notably used by air traffic controllers and pilots. These data include a broad range of radar data, meteorological data, aircraft positions and flight plans, and instrument landing system (ILS) data.
The processing of all this information requires powerful computing means. Among these means, the interfaces with data centers and decision-makers are of particular importance. These interfacing means serve notably for information routing to ensure that data finds its way to the right destinations. Given the very large volumes of data, the performance of these means is of vital importance in the global operation of an air traffic management system.
Commercially-available equipment exists with operating systems that can satisfy these routing needs. For example, there is a range of products carrying the registered brand name xe2x80x9cLINESxe2x80x9d, meaning xe2x80x9cLink Interface Node for External Systemsxe2x80x9d. These modular products are designed to enable routing and processing of input/output messages carried on incoming/outgoing serial links and Ethernet networks. Standard serial links, using protocols such as X25, HDLC and BSC for example, can be handled, as can dedicated lines, such as special radar data transmissions protocols.
These so-called routers can operate with a software architecture of frontal processor type. They are equipped with FPBSS-type software, meaning xe2x80x9cFront Processor Basic System Softwarexe2x80x9d. In this operating mode, the router is connected to a single application program. It has only one upstream function, for example routing data to the required destination. The essential application software is stored in one or more central computers; one router is required for each application.
The performance of these routers can be enhanced by using an open communication mode known as OCP (Open Communication Processor). In this mode, a router is connected to several applications and operates substantially as a data server. It is notably used to process and route the data from any input point to any output point. This operating mode is particularly suitable for air traffic management. In an air traffic management application, this mode notably provides the following functionalities:
black-box-type distribution of radar data to the centers, the radar data being received via serial interfaces and transmitted via an Ethernet network to an identified group of machines; such distribution is known as xe2x80x9cUDP multicastxe2x80x9d;
autonomous conversion of messages or protocols, notably enabling conversion of message formats or specific protocols, for example ISR2 into ASTERIX, X25 into HDLC-UI, etc.;
a line control function in radar systems, in other words retransmission of radar data via serial lines to processing circuits.
Among all the types of serial lines, covered by a library of communication protocols, we find different types of software interfaces and therefore of services. A specific interfacing program, usually referred to as an Application Programming Interface (API), can provide a common interface for access to any input or output, whether it be a serial or Ethernet link. This application notably issues requests to initialize or configure the inputs/outputs, for example to initialize a TCP/IP or X25 connection, and to send or receive messages to or from the inputs/outputs according to a predefined routing program. In this manner, it should not be necessary to develop a specific interfacing program every time a new interface needs to be installed. The API program is for example incorporated in an intermediate software layer, known as xe2x80x9cmiddlewarexe2x80x9d, superposed on the router""s system kernel or operating system.
In air traffic management applications in particular, there is a plethora of possible communication protocols all operating in different manners. For example, but not exclusively, there is a multitude of radar types to which a router can be interfaced. The API program described above is then no longer able to manage all the possible interface types. Although it is possible to develop API programs for each new type of interface, such a solution is not economically viable; moreover its complication has obvious negative impact on operational reliability and system maintenance.
One goal of the invention is to overcome the drawbacks previously mentioned by using a router able to manage a multitude of different interface types economically.
For this purpose, the invention is a data router communicating with systems via serial links, characterized in that it includes at least:
a generic routing program,
a first-level interface program (or API: Application Programming Interface) common to all the systems with which said router communicates,
a second-level interface program (or API) common to all said serial links, said generic routing program dialoguing with said first-level API, which in turn dialogues with said second-level API.
The main advantages of the invention are that its improves the reliability of a router, facilitates its maintenance, and adapts to a broad range of applications.